Space telegraphy.



` S. GABOT. .SPACE TBLEGRAPHY.

- APPLIOATIONPILBD nso. 31,1906.

937,281, patented 0@1;.19,1909.

4 SHEETS-SHEET 1.

Wl-r 552,25:

Patented 0G13. 19, 1909.

4 SHEETS-SHEET 2.

Num

Patented Oct. 19, 1909.

4 SHEETS-SHEET 3.

Wfl'. 55555: MJQEPITCIR: 6D, .f'ww @www CLM# @M-@m www To alliwhom it may concern:

UNITED sii-Aras rATENT OFFICE.

SEWALL CAIOT, F SR-QKLINE, MASSACHUSETTS. A

. SPACE TELEGRAPHY.

,Specicationof Letters Paten/c.I

Patented oct'. 19, 1909.

Application led December V31,1996. Serial No. 350,256.

Beit known thaty I, SEWALL Casor, a citi- .zen of the United States, anda resident of Brookline, inthe county.of,Norfolk and vio State of Massachusetts, have invented a new and useful Improvement in Spacev Televra phy, of which the 'following'is a speci cay tion.

My invention relates to space telegraphy and more especially to space telegraph transy .mitting systems in which ay large amount of electrical energy is radiated inthe form of electromagnetic waves.

, In space telegraph systems in which aso-f norous or oscillating circuit 'is'.as'soclated .with a radiating conductor, theiamoiintlpf energy absorbed by said sonorous-circuitin a given unit `oi time from the prime source of energy of agiven potential-is adirect'f function' of the capacity of the condenser included in said sonorous circuit and ofthe" frequencyfpof the vspark and is `equal yto CV where C,y represents the capacity of said condenser, V .the appliedpressurefand" 1 n the frequency of the 'current in the pri# mary power circuit. In such systems, es pecially wherethe association or cou ling of the oscillating circuit with the `radiating' conductor is effected by means f-"of'av magnetic` lield, a limitation tothe m'axiin'um'l capacity that maybe included `in -the oscillatingl circuit, for electrical oscillations of a givenl frequency and with a source of energy of given potential, is imposed by` the fact that ya certain-.minimum of inductance is required'-` to maintain an effective coupling and also to maintain the persistency of said circuit. 'Before this minimum of inductance is reached, the frequency of the oscillating circuit may vbe increased by reducing the inductance of said circuit; but after said minimum lof iii-O ductance has been reached the maximum frequency of said circuitwith a givenV energy .absorption remains lixed, thereby limposing a limitation upon the usefulness of the s .1stem which includes said circuit] for select 'We 'communication with a number of` receiving systems some of which may be attuned'" to respond to a higher vfrequency thanthe aforejsaid maximum. y

Certain engineering difficulties militatea' ainst increasing the energy which lmay be. -asorbed in an oscillating circuit by increas-I the vfrequency of the current in thev'pri- ,mary power circuit.

e One-of the objects of my invention, therefore, i's to provide aI space telegraph transmitting system in which the ener y absorbed increased without unduly increasing the, ca-I pacity of said sonorous circuit, the potential of the prime source of power or vthe frecircuitras,I for example, onefin which a sor'norous circuit including a condenser of relatively small capacity, say, .015.mcrofarads, g may be used to absorb a relatively large unit ottime from-.a primary pjower circuit'which is. energized by a commercial y 'alternatorgo ordinary lowfrequency, say,

"60 cyclesper second.

'tiveness ofthehuma'n ear to sonorous vibrations produced by `a magneto .telephone re" ,Vc'eiv'er energized v,by Avibratory currents'is a functioniof the frequency of said currents and thatthe frequency 'of said sonorous vibras) i tions-for which the ear is most sensitive is of Sound, page 473. AlsoV it is a fact that as the frequency 'of said sonorous vibrations vibrationsl per second, the sensitiveness of thevear'to sald vibrations increases as a high power kof such increase 1n frequency. For

128. to640, the-sensitiveness is increased in "the `ratio 64 tov 1. --`While .itis possible by means of aspeciall designed alternating current generator glving` a relatively high electrical oscillations having a, spark frequency of the order of 640 per-'second so that the rate of vibration of the currents in the local receiving circuit including a teleit is desirable as aforesaid to employ in the priinarypowe'r circuit a vibratory current not greatly exceeding 60 cycles per second 1n frequency.

is toprovide a space telegraph transmitting system in which, by means ofV an alternating uency, electrical oscillations havin a spark of said' alternating current may be devels opeato the ends-not only that a circuit in"- by the sonorous circuit from t e primary 69 V power circuit in a given unit of time may be quency of the current in-said primary power" amount of energy at a given potential in a 7j Itis now" well understood that ,the sensi `7,5

abfnit'lt() per second, seeRayleigh', Theory is. increased from that vwhich marks the 83 lowerA limitof audibility up to about 640 y ,current ofv ordinary commercial low rerequeney. much higher than the requencv 113 cluding a condenser ofrelatively small ca? pacity may bevemployed as aforesaid to ab- J sorb in a given unit of time a relatively large j amount of energy from a'prime sourceof lpower of given potential, but also `that .the vtelephone receiverat thee-receiving station maybe energized by currentsy of tho'sefrequenci'es t'o vwhich the humaneear is most sensitive.

(Further objects of 4invention?"'aretoV providel a discharger for the condenser of-ja 'sonorous circuit comprisinga spark gap' constructed and arranged to alter the energy absorbed by said sonorous circuit vvith'1 out alterin the length of said gap, and also constructe and arranged Vso* that an vair blast may be created byl one member thereof and directed across the lgap to revent, or;

at least to diminish, arcing at sai gap'.

Myl invention may best be understood by V having reference to 'the' drawings which accompany and form apart of'thisfspeciication and which illustrateone of the many possible embodiments of the discharger vclearness. Fig. 3 is, an end viewpartly in l, section of one of the rotating electrodes and Fig. 4 4is Ia side view also partly in section thereof. Fig. 5 shows a 'section taken on a line 5 5 of` 2 looking toward the right. Fig. 6 is a fragmentaryview showing part of a central vertical section of the discharger illustrated in Fig. 2 and including the aforesaid funnelvl6.

In Fig. 1V is anelevated conductor, E is an earth connection, M Ml are transformersC is a condenser- S is a spark gap, L L

are inductan'ces,'I1 -I2` are the primary and .crease the energy absorbed per second by 'secondary -respectively of the transformer yM, B isa motor or prime mover of any suitable type, K isa key, A isla source of vibral tory current and R is a rheostat or other suitable means for regulating the output of thek source A.

,i plurality" of i series,l of stationary electrodes, one series belng shown for purposes of illustration asy having 12 electrodes b, and the' otherseries as having a like number of electrode'sbf The respective members of the Aseries ofstationary electrodes are arranged so that each one in series b vis directly oppothe corresponding electrodes of the other series. For example, b'1v is directly opposite1 b1', b2 is directly opposite b2 and I), 1s directly o posite bsand the distances between each palr of electrodes are all exactly equal, so that the planes determinedby the extremitie's of the. two series of electrodes are parallel.' `A movable member of conducting material having three electrodes c1 c, and 0 is'arranged to `rotate between the two series of stationary electrodes, and the movable electrodes may -be so positioned as, to be equidistant. from4 the planes determined by vthe ltwo-series of stationary electrodes. The" movable electrodes are arranged symmetricall'y'witli respecty to the ystationary electrodes so' thatvthe movable electrodes, respectively, always are equidistant fromv a pair of stationaryielectrodes. For example, in the position shown in Fig. l, the distances b1 c1 bl',

b2 c2 b2', and b3 c3 b3 are equal. The ap S therefore is multiple-series spark gap and 'electrical discharges simultaneouslytake place always through three aths which are. 1n multiple with respect to t e sonorous circuit-S I1 C. v e

' Any suitable means may be employed for rotating the movable electrodes and in the present instanre'I have shown the same connected by a belt to the prime mover B, which is Apreferably so designed as to rotate the movable electrodes at a relatively high speed. It will be understood of course that I donot limit 'myselfto any particular number of series of stationary electrodes or to any particular number of electrodes in each of saidl series or to any particular number lof movable electrodes or to any particular rotational speed ofthelatter; but I prefer to so relate the speed of rotation of the movable electrodes with the number of the stationary electrodes that the condenser C will be discharged about 640'times er second. By thus discharging said' con enser about 640 times per second,-in other words, by creating inthe sonorous circuit electrical oscillations having'a spark frequency very much greater than the frequency of the currents elivered by the source A,-I greatly v inthe sonorous circuit from lthe primary power circuit. Thus for example, if the frequency of the source A is cycles per second, the spark frequency of the oscillations created in the sonorous circuit by discharging the condenser thereof through a spark gap of the usual type would be about 120 er second; but by charging and discharging'the condenser 600 times per second in lieu of 120 times. per second, in accordance with the present invention', I increase the energy absorbed per second `by the sonorous circuit from the primary power circuit in the ratio' of 5 to 1, and I also produce in the circuit of the telephone receiver at the A j senesi' frequency'of themaA sonorous Avibrationsgto`v vwhich the huma1`- 'ear is. mostsensitive.

' f Whileany suitable-key or'sending device may be employed `for controlling the current 'supplied to the# sonorous circuit in acc/ord'- ance with the signal to be sent, I prefer to use the rtype of key shown at Kin which` the members aand o form a series gap in "theintermediate=eicuit vbetween the pri- Ato. y750.00 volts, the rheostat R is adjusted mary power circuit and the sonorous circuit.

"When the key is` held by the-spring e' in its normal or open position, the 'resistance of saidseries gapis too great to permit the complete charging of the condenser Cand when said key is depressed the series gap is of sufficiently low resistance to permit the potential impressed upon'its terminals. to

Yarcl across the -same and fully charge said condenser. l

Itwill be readily apparent that `a spark gap of the kind herein. described will automatically 'alter the energy-absorbable by the 'sonorous' circuit in a givenunit of time and therefore render any alteration of the length Aof the spark gap unnecessary, for the distances between each corresponding pair of stationary electrodes, such as b b, b2 b2', b3

, b3', etc., are such that under no conditions .of

operation will a spark` pass directly therebetween and it is only when one of the conducting members c, c, c3 is moved up into proximity to a pairjof stationary electrodes that thel condenser C will discharge. The position of a movable electrode withlrespect to a pairof stationary electrodes at which sparking will take placev depends upongthe adjustment of the rheostat R or other current regulatingdevice in the primary powercircuit. The generator A, rheostat Rand transformer M are-of course so adjusted with respect to the distances'betyveen the stationary electrodes of one seriesthat there can be-butone path for the dischargel of the condenser C between a member of the series b, a movable electrode and a 'member of the consequently, equidistant from two members of the series 7J. If, therefore, we assume that the velectrode .c1 is equidistant from .b1 andthe electrode of the series b next below 1) and, consequently, is equidistant from the electrode 1), and that electrode of the series b' whichis next below b1', no spark will pass; but when c, m ves past such -mi'dwa position toward-b1* i?, a spark will pass rom b,

to b1 by strength of the yrapt1 c, b1 becomes' suffciently small to be ruptured by the dieri way,` of c, when .the dielectric ence of otential between the series e and the series b1 Clearly, therefore, by l regulatin the primary power circuit by the rheostat or. other suitable device, the, potential to y which the condenser C may become charged, said potential below the maximum possible depending upon the length of its discharge path, may be automatically adjusted by the spark gap or discharger itself. For example, i it be desired to charge the condenser YC until the difference of potential between the series b and vb is 75000 volts and then, when l the gap between said two series via a movable electrode becomes equal tothat which `will'y break down at 475000 volts, the condenser discharges at three points simultaneously from b to b via the three movable "electrodes respectively; and, in like manner,

if itbe desired to charge said condenser C merely to 5000 volts, the rheostat R is adjusted until the difference of potential between the series b and b is 5000 volts, in

'which case the condenser C will discharge as beforefat three points from b'to ,b via Vsaid three movable electrodes respectively,

when the gap between b and b at each of sai'd points becomes suiiciently small to be v broken dowri by 5000 volts'.

The inductances L L.- are sorelated to the other inductances and to theV capacit of the circuit M', L I, C La a that the in uctance reactance of said circuit foralfternating currentsA of the frequency lg'eneratec-lv by d the source A is practically equal and op osite in' sign to the capacity Vreacta'nce of Sai circuit, *soy that while the condenser C is charging practically the only opposition tol the development of current in said circuit is the ohmlc resistance thereof. When said condenser L E.

discharges across the gap S, the condenser is practically short-circuited with res ect to the secondary of transformer M y the s ark so thatY during such discharge the inuctance reactac'eofthe coils` L L is not neutralized by the capacity .reactance of said condenser, and therefore said secondary is 'not short-circuited by said spark and the rre potential at' its terminals is maintained.

The oscillatory discharge of the condenser C takes place, even when the sonorous circuit is very persistent, in an interval of time very much smaller than that required `for one of the 'movable electrodes to pass between two consecutive stationary electrodes of one sen ries, so that no difficulty is encountered in creating as many prime discharges of said condenser, lor as many trains of oscillations, as. desired during the contlnuance of each half cycle of alternatingV potential in the primary power circuit.

It will be obvious that the discharger, the principle of which has been explained above 1n connectionl with the conventional showvingfinr Fig. 1, may be embodied in a greatr lilla variety of working apparatus, and accordingly I desire to'be understood that the particular working apparatus which is now to be explained in connection with Figs. 2 to 6 inclusive, is included herein merely for the purpose of more fully disclosing my invention and that it is not in the nature of a limitation.

- In. Fig. 2,. 1 is 'a casing which maybe of hard 'wood,' inclosin an inner casing 2,

which maybe of rub er or other insulating materiaL-:and the space between said casings may belille'd with mineral woolA 3, or other suitable'material' for deadening the sound of the spark zdischafges. The shaft 7 is .journaled in thefstandards 11 11 ,which may be provided'with the pulley 12- adapted to receive abelt from any suitable type of'prime mover, yand carries one -or more disks 8 82 I of conductingr material whichare secured to f the insulating bushing 8. `Each disk is rovidedasshown inthe resent case with t ree electrodes c, o2 c3', c', c 2 c', which preferably are securedI tan entially to the disks.

. By means of the clips '4 4', the plates 5 5- are heldin position at the ends of the inner casing 2, landv each plate carries'a series of stationary electrodes b, b3, respectively. Thev centralpartition '6 of conducting' material carries two oppositely arranged seriesof stationary electrodes b b?. vThe movable electrodes are arranged as shown in the spaces between these'ries of stationary electrodes b b and b2 bs,'respectively. The plates 5 5 are connected to the binding posts 10 10 respectively, and the discharger is connected with the sonoros circuit by means of said binding posts as indicated by the numerals 10 l0 in the diagram shown in Fig. 1. The

clips 4t 4 which terminate in the aforesaid bindin posts may be surrounded by. insulating ushings.9 '..9f.f 13 1,3 and 14 14 are .Ventilating apertures. u. Wlilelvarious means may be employed for creatiiig a blast of air and, directingthe same across the spark gap for preventing arc1ng,lI prefer as shown in I the fragmentary view illustrated'in Fig. 6,

' order to.conline the air in said space the to inserta tube 15 terminating in a funnel 16 through the casings and surrounding the shaft 7 so that the movable electrode itself will operate as a blower, drawing air into the inner casing and directing an air-blast of considerable'force through the space between the terminalsl ef, the oppositely arranged series of stationary electrodes. In

shield 17 may be arranged as shown within the series of stationary electrodes op osite that within which the funnel 16 is p aced. It will be understood 'of course that a similar inlet tube, funnel and shieldfareprovided for the second set of electrodes b2 b3 which are shown in Fig. 2, and that for .the sakeof clearness these details have not been illustrated in said Fig. 2.

I do not wish to be understood as limiting myself to the structural details or circuit arrangements which I have herein specifically `described for the purpose of more fully dis- -tionary members, a movable member, and

means creating' relative movement between said stationary members and movable member.

3. A discharger for the condenser of a sonorous circuit having in combination a pluralit of stationary electrodes connected in multiple, a movable electrode consisting of a plurality of conducting members sym-l metrically arranged with respect to said stationary electrodes, and means for creating relative movement between said elec v 4. The combination with a sonorous circuit of amultiple series spark gap having a. rotating member.

. 5 The combination with a sonorous circuit of a multiple series spark gap having stationary members, a movable member, and means 'creating relative movement between said member.

6. The combination with a sonorous circuit of a. multiple series spark gap having a plurality of rotating members.

7. The combination with a sonorous cir- 4cuit of a multiple series spark gaphaving` stationary members, a plurality of movable members, and means creating relative move- .ment between said stationary members and movable members.

8. The combination with a' sonorous circuit of a multiple spark gap having a plurality of rotating members.

9. The combination with a sonorous circuit of a multiple spark gap having stationary members, a plurality of movable members, and means creating relative movement between said stationary members and movable members.

stationary members and movable 10. The combination with a sonorous crvcuit of a series spark gap having a plurality of sets. of stationary members and a plurality of sets of rotating members.

11. The combination with a sonorous circuit oi' a series spark gap having a plurality of sets of stationary members, a plurality of movable members, yand means creating relative movement between said stationary members and movable members.

12. The combination with a sonorous circuit of a multiple series spark gap having a plurality of sets of stationary electrodes, and a movable electrode arranged between adjacent members of said sets of stationary electrodes.

13. The combination with a sonorous circuit of a multiple series spark gap having two sets of stationary electrodes and a movable electrode arranged therebetween.

14. The combination with a sonorous circuit of multiple series spark gap for dis charging the condenser thereof, said gap having stationary and movable members and being constructed and arranged to permit the increase of energy absorbed by said sonorous circuit without altering the separation of said stationary members.

In testimony whereof, I have hereunto subscribed my name this 29 day of Dec. 2 0

SEWALL CABOT.

VYitnesses:4 i

GEO. K. WOODWORTH, E. B. ToMLINsoN. 

